Personalmente, userei C # come linguaggio di scripting. Il framework .NET (e Mono, grazie Matthew Scharley) include effettivamente i compilatori per ciascuno dei linguaggi .NET nel framework stesso.
Fondamentalmente, ci sono 2 parti nell'implementazione di questo sistema.
Consentire all'utente di compilare il codice È relativamente facile e puòessere fatto solo con poche righe di codice (anche se potresti voler aggiungere una finestra di dialogo di errore, che probabilmente sarebbe un paio di dozzine di righe di codice in più, a seconda di come è utilizzabile vuoi che sia).
Creare e usare classi contenute nell'assembly compilato Questo è un po 'più difficile del passaggio precedente (richiede un po' di riflessione). Fondamentalmente, dovresti trattare l'assembly compilato come un "plug-in" per il programma. Ci sono alcuni tutorial su vari modi in cui puoi creare un sistema di plug-in in C # (Google è tuo amico).
Ho implementato un'applicazione "rapida" per dimostrare come implementare questo sistema (include 2 script funzionanti!). Questo è il codice completo dell'applicazione, basta crearne uno nuovo e incollare il codice nel file "program.cs". A questo punto devo scusarmi per il grosso pezzo di codice che sto per incollare (non intendevo che fosse così grande, ma mi sono lasciato un po 'trasportare dai miei commenti)
using System;
using System.Windows.Forms;
using System.Reflection;
using System.CodeDom.Compiler;
namespace ScriptingInterface
{
public interface IScriptType1
{
string RunScript(int value);
}
}
namespace ScriptingExample
{
static class Program
{
///
/// The main entry point for the application.
///
[STAThread]
static void Main()
{
// Lets compile some code (I'm lazy, so I'll just hardcode it all, i'm sure you can work out how to read from a file/text box instead
Assembly compiledScript = CompileCode(
"namespace SimpleScripts" +
"{" +
" public class MyScriptMul5 : ScriptingInterface.IScriptType1" +
" {" +
" public string RunScript(int value)" +
" {" +
" return this.ToString() + \" just ran! Result: \" + (value*5).ToString();" +
" }" +
" }" +
" public class MyScriptNegate : ScriptingInterface.IScriptType1" +
" {" +
" public string RunScript(int value)" +
" {" +
" return this.ToString() + \" just ran! Result: \" + (-value).ToString();" +
" }" +
" }" +
"}");
if (compiledScript != null)
{
RunScript(compiledScript);
}
}
static Assembly CompileCode(string code)
{
// Create a code provider
// This class implements the 'CodeDomProvider' class as its base. All of the current .Net languages (at least Microsoft ones)
// come with thier own implemtation, thus you can allow the user to use the language of thier choice (though i recommend that
// you don't allow the use of c++, which is too volatile for scripting use - memory leaks anyone?)
Microsoft.CSharp.CSharpCodeProvider csProvider = new Microsoft.CSharp.CSharpCodeProvider();
// Setup our options
CompilerParameters options = new CompilerParameters();
options.GenerateExecutable = false; // we want a Dll (or "Class Library" as its called in .Net)
options.GenerateInMemory = true; // Saves us from deleting the Dll when we are done with it, though you could set this to false and save start-up time by next time by not having to re-compile
// And set any others you want, there a quite a few, take some time to look through them all and decide which fit your application best!
// Add any references you want the users to be able to access, be warned that giving them access to some classes can allow
// harmful code to be written and executed. I recommend that you write your own Class library that is the only reference it allows
// thus they can only do the things you want them to.
// (though things like "System.Xml.dll" can be useful, just need to provide a way users can read a file to pass in to it)
// Just to avoid bloatin this example to much, we will just add THIS program to its references, that way we don't need another
// project to store the interfaces that both this class and the other uses. Just remember, this will expose ALL public classes to
// the "script"
options.ReferencedAssemblies.Add(Assembly.GetExecutingAssembly().Location);
// Compile our code
CompilerResults result;
result = csProvider.CompileAssemblyFromSource(options, code);
if (result.Errors.HasErrors)
{
// TODO: report back to the user that the script has errored
return null;
}
if (result.Errors.HasWarnings)
{
// TODO: tell the user about the warnings, might want to prompt them if they want to continue
// runnning the "script"
}
return result.CompiledAssembly;
}
static void RunScript(Assembly script)
{
// Now that we have a compiled script, lets run them
foreach (Type type in script.GetExportedTypes())
{
foreach (Type iface in type.GetInterfaces())
{
if (iface == typeof(ScriptingInterface.IScriptType1))
{
// yay, we found a script interface, lets create it and run it!
// Get the constructor for the current type
// you can also specify what creation parameter types you want to pass to it,
// so you could possibly pass in data it might need, or a class that it can use to query the host application
ConstructorInfo constructor = type.GetConstructor(System.Type.EmptyTypes);
if (constructor != null && constructor.IsPublic)
{
// lets be friendly and only do things legitimitely by only using valid constructors
// we specified that we wanted a constructor that doesn't take parameters, so don't pass parameters
ScriptingInterface.IScriptType1 scriptObject = constructor.Invoke(null) as ScriptingInterface.IScriptType1;
if (scriptObject != null)
{
//Lets run our script and display its results
MessageBox.Show(scriptObject.RunScript(50));
}
else
{
// hmmm, for some reason it didn't create the object
// this shouldn't happen, as we have been doing checks all along, but we should
// inform the user something bad has happened, and possibly request them to send
// you the script so you can debug this problem
}
}
else
{
// and even more friendly and explain that there was no valid constructor
// found and thats why this script object wasn't run
}
}
}
}
}
}
}